Rock-anchoring devices with non-metal components

ABSTRACT

Devices for attaching to rock that have non-metal components and can be used for rock climbing. Embodiments include passive chocks, active camming devices, passive camming devices, and sliders. Lightweight materials used in place of more dense materials like steel result in lighter weight devices. Geometry of parts are changed to reduce weight, reduce manufacturing cost, and increase functionality. Higher friction materials against the rock allow greater expansion ranges, less stress in the rock, and increased holding power. Many embodiments have a head attached to a stem and a loop. Various embodiments feature nonmetallic tensile members, tubular plastic semi-rigid stems, polymer cams, hollow or non-metallic axles, biasing mechanisms, high-friction materials on one side or both, or combinations of these and other features.

FIELD OF INVENTION

[0001] This invention relates generally to systems and devices for attaching to rock.

BACKGROUND OF THE INVENTION

[0002] People have probably been climbing on rocks since well before such activities have been recorded, probably both to get to places that are otherwise inaccessible, and for adventure. However, the risk of serious injury or death from a long fall prevented most people from climbing very high above the ground on difficult climbs until in recent decades, technology has been developed that makes rock climbing much safer. Since that time, rock climbing has become an increasingly popular sport, combining physical, mental, and emotional challenges, and typically being performed in some of the most beautiful natural settings in existence. In addition, the mutual dependence between rock climbing partners facilitates camaraderie not often found in other recreational activities or in modern life.

[0003] Rock climbing is made relatively safe through the use of a rope, various anchors which are attached to the rock, and teamwork between typically two climbers at a time. When climbing up, the rope is typically attached to the lead climber who trails the rope below him as he climbs, periodically running the rope through a link with a spring-closed gate called a snap link or carabiner (also spelled carbiner or called a biner or a crab). The carabiner is typically attached to the rock through a short piece of rope or webbing (flat strap, typically made of nylon), and usually a device called a piece of protection (or just “piece”, “protection”, or “pro”) that attaches to the rock. The other climber or belayer feeds out (or takes in) the rope at a controlled rate through a device called a belay device, that is typically attached to the belayer, who may himself be anchored or attached to the rock. Thus, if the lead climber falls, her fall is stopped by the rope, typically a little more than twice the distance the lead climber is above her last piece of protection. Modern rock climbing technology has allowed climbers to climb routes that are right at the very limit of their physical abilities. This allows them to improve their abilities very efficiently, and the best climbers have been able to surmount climbs that were previously unimaginable.

[0004] A device that attaches to the rock may be either a bolt (e.g., an expansion anchor) or a device that anchors in a natural feature within the rock such as a crack or pocket, the latter device typically being called natural protection. Bolts require less skill to use than natural protection, and can be installed anywhere there is good solid rock. However, bolts require drilling a hole in the rock, and thus make a permanent change in an otherwise natural and typically very aesthetic setting. Thus many climbers and governmental land managing agencies frown on the placement of bolts, especially where natural protection is sufficient or there is another way to get to the top of the climb.

[0005] When rock climbing techniques were first developed in the United States, protection in cracks or pockets typically consisted of metal spikes or pitons that were pounded into a crack with a hammer. However, pitons often damaged the rock. Therefore, virtually all climbing in the United States that utilizes cracks or other natural features for protection has switched to less destructive methods that typically do not require the use of hammers. The first such devices were chocks, which are simply a solid or hollow head typically made of aluminum, attached to a loop of rope or wire. Chocks are said to be passive devices, since they have no moving parts and are not actively pounded into the rock. The head of a chock is typically placed in a crack at a location where the crack constricts in the downward direction, and the carabiner is typically attached to the rope or wire. Chocks are still widely used today, typically in smaller sizes (e.g., one inch and smaller), typically mounted on steel or stainless steel wires. Such chocks are typically called wired nuts or just nuts. However, chocks and nuts require a restriction in a crack to be in the downward direction, and such conditions or placements are not always available when desired.

[0006] Another device in wide use today are spring-loaded camming devices (SLCDs), also called active camming devices as opposed to passive devices such as chocks. SLCDs typically include a head that has three or four cams rotating on an axle, a stem attached to the head, (e.g., at the axle), and may have a loop of rope or webbing attached to the stem at the opposite end from the head. The carabiner typically attaches to the loop. As the name implies, SLCDs typically also have springs in the head that bias the cams to rotate against the rock, and a trigger mechanism on the stem, or between the stem and the head, that allows the climber to retract the cams for placement into the crack or pocket, and for removal therefrom. The cams are typically substantially spiral or elliptically shaped so that a pull on the stem causes the cams to rotate and expand, increasing the force against the sides of the crack. Thus, SLCDs can be used in parallel sided cracks, or even cracks that are slightly flaring, i.e. in the direction of the pull. Further, in comparison to nuts or pitons, SLCDs are typically relatively easy to place and easy to remove.

[0007] Examples of prior art rock anchoring devices are found in U.S. Pat. Nos. 4,184,657, 4,643,377, 5,860,629, 5,934,635, 6,042,069, 6,092,773, 6,273,379, 6,283,426, and 6,375,139, each of which is herein incorporated by reference in its entirety.

[0008] In the prior art, the axles of SLCDs were typically solid steel. The stems of SLCDs were originally rigid, being made of a piece of aluminum bar. However, such aluminum stems may be damaged into inoperability when loaded , for instance, by bending (e.g., when the device is placed in a horizontal crack and the leader takes a fall). Later SLCDs used a steel or typically stainless steel wire rope or cable stem, which was not as susceptible to damage when loaded in bending. Some devices had a “U” shaped wire rope stem or U-stem that attached to both ends of the axle.

[0009] Where wire rope was used, it was typically silver soldered at the ends, (e.g., to a block of stainless steel that the axle passed through). In the prior art, the cams of SLCDs were typically made of aluminum. Some cams were textured in an attempt to increase the friction between the cam and the rock; however, the friction was typically limited to what can be expected between rock and aluminum. This coefficient of friction between rock and aluminum substantially determined the angle of the spiral or ellipse of the cams, and thus the range of crack sizes that a given SLCD will anchor in or attach to.

[0010] A lead climber on a naturally protected route typically has a collection of different sizes (different size heads) and types (e.g., chocks, SLCDs, and possibly other types) of protection for the various sizes and shapes of cracks and pockets (placements) he anticipates encountering on the route. This collection is typically called a lead rack (or just rack), which typically includes a collection of slings (loops of rope or webbing) and carabiners that the leader may need to protect herself on the climb and to set up an anchor at the top (top of the climb or a place to belay before the end of the rope) to belay the second climber from. When the second ascends, he removes the pro as he goes. Climbers typically have to seek a balance between a desire to have as much pro as possible available for use and a desire to have as light of a rack as possible. A heavy rack is a disadvantage not only on the technical climb where the climber may be climbing at the limit of her abilities, but in many instances, also on the hike to the base of the technical climb, which for some remote climbs may also involve carrying heavy backpacking equipment as well.

[0011] In the prior art, pro typically included ferrous materials such as steel and stainless steel, which, although strong, are quite dense. These ferrous materials comprise a substantial amount of the weight of a typical climbing rack, and limit the number and size range of the pieces of pro a climber can include in the rack. In addition, in the prior art, the heads of pro, such as chocks or SLCDs, were typically comprised of metal such as aluminum. Although relatively light for a metal, the heads or cams typically comprise a substantial amount of the weight of pro, especially in the larger sizes. This weight further limits the number and maximum size of the pieces of pro a climber can include in the rack. Furthermore, the use of aluminum in the cams of SLCDs, which has a relatively low coefficient of friction against rock, limits the shape or angle of the cams, and thus their expansion range. Therefore any given SLCD will only work in a fairly small range of crack widths, and may not work at all or may be unsafe in placements where the crack is substantially wider for some of the cams than for the others.

[0012] Accordingly, a need exists for devices which attach to features in rock such as cracks and pockets, wherein the devices are lighter, function in a wider range of crack sizes, reduce the stress on the rock, attach more securely to the rock, are less expensive to manufacture, or are easier to use than the prior selection of devices available. It is further desirable that the different sizes of these devices be easily distinguishable, and that to the extent practicable it be possible to replace parts of the devices when worn or damaged.

SUMMARY OF THE INVENTION

[0013] The present invention provides systems and devices for attaching to rock. The present invention may be used for rock climbing, (e.g., protecting a lead climber or setting up belay anchors), and may be placed in natural features in the rock such as cracks or pockets. Various embodiments of the present invention include passive chocks or nuts and active camming devices or spring-loaded camming devices, and passive camming devices. Some embodiments utilize light weight materials in place of more dense materials such as steel, stainless steel, or aluminum thus resulting in lighter weight devices or systems. In some embodiments, the geometry of parts are changed to reduce weight or increase functionality. The lighter weigh allow climbers to carry more or larger pieces of protection on their rack, or may reduce the weight of the rack. In addition, various embodiments of the present invention have a higher coefficient of friction between the rock and the device, thus allowing greater size ranges and providing less stress on the rock. Another feature of some such devices in accordance with the present invention is that they may be configured to increase the holding power of the devices in comparison with the prior art. Additional features of various embodiments of the present invention are that they are inexpensive to manufacture, easy to select the correct size, and easy to repair or refurbish if ever needed. Benefits of the present invention include that various embodiments may make rock climbing safer and more convenient, and may allow climbers to climb longer, more remote, and more difficult routes. These and additional features and benefits of the present invention are described in more detail below and will be apparent based on the description herein to a person skilled in the art.

[0014] An exemplary embodiment of the present invention provides a device for anchoring to natural features in rock that includes a head, a stem, and a loop. The stem is attached to the head and may be at least semi-rigid. The stem may have a tensile strength greater than 1500 pounds, and generally has at least one polymer tensile member that substantially provides the tensile strength of the stem. In other words, the tensile member may provide more than 75 percent of the tensile strength of the stem. The loop may be connected to or integral with the stem, and is generally configured to attach to a carabiner, a sling, or both.

[0015] In various embodiments the device may be a chock or nut and the head may be a single piece of material such as metal or polymer which (in the case of a polymer) may be fiber reinforced. In other embodiments, the device may be a spring-loaded camming device and the device may have at least three cams, at least one axle, a plurality of springs, and a trigger mechanism. The cams may be comprised substantially of polymer material which may be fiber reinforced. The loop may be formed with a flexible, non-ferrous tensile member, which may continue through the stem and may further continue around the axle. The stem may utilize a hollow plastic tube, and the head, the tensile member, and the tube, may be configured so that the tube is attachable to the head with an interference fit. The tube may be color coded or marked to indicate the size of the head. The tensile member may be located within the tube and may be made of a substantially flexible material such as rope or webbing, which may also form the loop. On the other hand, in various other embodiments, the stem may be fiber-reinforced plastic. Thus, in many embodiments, the stem may utilize no load bearing ferrous materials at all.

[0016] The present invention also provides in another exemplary embodiment a camming device configured to attach to natural features in rock that has a head with at least one cam that includes a non-metallic material. The non-metallic material may be at least ten percent of the weight of the cam. The device may also have a stem attached to the head, and the stem may have at least one non-metallic tensile member. The head may also have a biasing mechanism and the non-metallic material may be a high-friction material. In some embodiments, the head may have at least one axle and a trigger mechanism, and there may be at least three cams on the axle, which may be substantially non-metallic. The axle may be hollow, substantially comprised of aluminum, or substantially comprised of a polymer material. The stem may have a hollow plastic tube that contains the tensile member, which may be substantially flexible and may form a loop configured to attach to a carabiner. The trigger mechanism may further have a plurality of substantially nonmetallic trigger leads attached to the cams.

[0017] In addition, the present invention also provides in another exemplary embodiment, a camming device configured to attach to natural cracks or pockets in rock, which may have features in common with the exemplary embodiments described above. This embodiment has at least three cams, which may be made of a non-metallic material, at least one axle, a trigger mechanism, and a stem which may be at least semi-rigid. The cams may be comprised substantially of fiber-reinforced plastic, and the axle may be hollow. The axle may be substantially comprised of aluminum or a polymer material (e.g., fiber-reinforced plastic), and may have bushings between the cams and the axle. The stem may have a hollow plastic tube containing a tensile member, which may be substantially flexible and may also form a loop configured to attach to a carabiner. In other embodiments, the stem may be made substantially of fiber-reinforced plastic, and may forgo any load bearing ferrous materials. The trigger mechanism may be made with another hollow plastic tube, and may also forgo any ferrous cable.

[0018] Still further, the present invention also provides, in another exemplary embodiment, a device for attaching to a feature in rock that has two sides which are substantially opposite each other, where at least one of the sides includes a high-friction material. This embodiment may have a head with two surfaces on substantially opposite sides of the head, a tensile member attached to the head, and a loop configured to attach to a carabiner that may be joined with the tensile member. The device may be configured to anchor to the feature in the rock with one surface in contact with one side of the feature, and the other surface in contact with the other side. In some embodiments, the second surface may not be a high-friction material, and that second surface may be metal. In such embodiments, the tensile member may be attached to the head proximate the surface that does not have a high-friction material (e.g., opposite the side with the high-friction material). Other embodiments may have high-friction materials on both surfaces. Various embodiments may also have a biasing mechanism, and in some embodiments, such as spring-loaded camming devices, the two surfaces that contact the rock may be movable with respect to each other. In various active and passive camming device embodiments of the present invention, the device may be configured to anchor to a feature that has substantially parallel sides.

[0019] These features of the three exemplary embodiments described may be combined in various combinations as would be apparent to a person skilled in the art of creating quality climbing or rock anchoring equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The figures in this document illustrate various exemplary embodiments of the present invention. Embodiments of the present invention may include part or all of the features shown in one of these drawings, or may include features from two or more figures. Embodiments of the present invention may also include features described in the specification, or limitations to features described in the specification. Furthermore, embodiments of the present invention may include features that would be familiar to a person of ordinary skill in the art having studied this document.

[0021]FIG. 1 is a front view illustrating an embodiment of a nut in accordance with the present invention;

[0022]FIG. 2 is an isometric view illustrating another embodiment of a nut in accordance with the present invention;

[0023]FIG. 3 is a front view of a single-axle four-cam spring-loaded camming device in accordance with the present invention;

[0024]FIG. 4 is an exploded partial cut-a-way isometric view of the single-axle spring-loaded camming device shown in FIG. 3;

[0025]FIG. 5 is a top view of the single-axle spring-loaded camming device shown in FIGS. 3 and 4;

[0026]FIG. 6 is a partial cut-a-way side view of the single-axle spring-loaded camming device shown in FIGS. 3-5;

[0027]FIG. 7 is a side view of a double-axle spring-loaded camming device in accordance with the present invention installed in a crack in a rock;

[0028]FIG. 8 is a partial cut-a-way isometric view of an alternate embodiment illustrating the stem and stem end of the single-axle spring-loaded camming device shown in FIGS. 3-6;

[0029]FIG. 9 is a side, partially sectional view illustrating an embodiment of the stem end and tube of the double-axle spring-loaded camming device shown in FIG. 7;

[0030]FIG. 10 is a sectional side view illustrating an alternate embodiment of the stem and loop of the single-axle spring-loaded camming device shown in FIGS. 3-6;

[0031]FIG. 11 is a partial cut-a-way isometric view of the alternate embodiment shown in FIG. 10;

[0032]FIG. 12 is a partial cut-a-way side view of another alternate embodiment alternate embodiment of the stem tube of the single-axle spring-loaded camming device shown in FIGS. 3-6;

[0033]FIG. 13 is a sectional side view illustrating another alternate embodiment of the stem of the single-axle spring-loaded camming device shown in FIGS. 3-6;

[0034]FIG. 14 is a partial cut-a-way isometric view of the alternate embodiment shown in FIG. 13;

[0035]FIG. 15 is a front view of a single-axle three-cam spring-loaded camming device in accordance with the present invention;

[0036]FIG. 16 is a partial sectional view illustrating the stem end of the single-axle spring-loaded camming device shown in FIG. 15;

[0037]FIG. 17 is a partial sectional view of an alternate embodiment of the stem end of the spring-loaded camming device shown in FIG. 15;

[0038]FIG. 17 is a partial sectional view of another alternate embodiment of the stem and stem end of the spring-loaded camming device shown in FIG. 15;

[0039]FIG. 19 is a side view of a camming device with a high-friction surface in accordance with the present invention, the device illustrated in a crack in a rock;

[0040]FIG. 20 is a sectional end view of the camming device of FIG. 19; and

[0041]FIG. 21 is a side view of the camming device of FIG. 19.

DETAILED DESCRIPTION

[0042] Systems and devices in accordance with the present invention provide an improved way for attaching to rock. The present invention may be used for various purposes including for rock climbing, such as protecting a lead climber relying on placements in natural features in the rock such as cracks or pockets. The present invention may also be used for setting up belay anchors, rappel anchors, and the like. The present invention may be used for recreational rock climbing, or other purposes such as construction, inspection, mining, and the like. As an example, it may be used to secure safety lines for workers engaged in removing loose rock from above a roadway.

[0043] Various embodiments of the present invention include passive chocks or nuts and active camming devices or spring-loaded camming devices. Embodiments may utilize light weight materials in place of more dense materials such as steel, stainless steel, or aluminum, and generally result in lighter weight devices or systems. In some embodiments, the geometry of parts are changed to reduce weight or improve functionality. For instance, axles may be made hollow, or cam angles may be increased. In the example of recreational rock climbing, the lighter weigh may allow climbers to carry more or larger pieces of protection on their rack, or may reduce the weight of the rack. In addition, various embodiments of the present invention which feature active camming devices have a higher coefficient of friction between the rock and the device, thus allowing greater size ranges and providing less load and stress on the rock. This feature makes it less likely that when a climber takes a fall, the rock will break, freeing the anchor, and knocking down pieces of rock. Various embodiments of the present invention may be configured to utilize the increased coefficient of friction to increase the holding power of the devices in comparison with the prior art. As will be explained in more detail below, various embodiments of the present invention are relatively inexpensive to manufacture, easy to use, and easy to repair.

[0044]FIG. 1 illustrates as an exemplary embodiment of the present invention, a passive device or nut 100 for anchoring to natural features in rock. As used in this document, natural features in rock include cracks, pockets, spaces under or between boulders, and other hollow or partially enclosed spaces naturally formed by the rock, and features in rock (without the word “natural”) may further include holes drilled or chipped into the rock. Features (natural or otherwise) may, for example, have two sides, which may be substantially opposite and may be substantially parallel. As used in this document, a crack generally is said to have two sides which are substantially opposite, even if there is a constriction in the crack, for instance that nut 100 could be lodged in. However, a passive nut 100 usually will not lodge adequately and reliably in a crack having substantially parallel sides.

[0045] Nut 100 includes a head 102, a stem 145, and a loop 170. Stem 145 may be at least semi-rigid and is securely attached to the head 102. As used in this document, “attached” means directly attached or (except where clearly otherwise) attached to one or more other components which are directly attached. As used in this document (except where clearly otherwise), “attached” does not include being integral with in a continuous piece of the same material. In some embodiments of nut 100, head 102 is integral with stem 145 in one continuous piece of material. In some embodiments, head 102, stem 145, and loop 170 are all integral. But in the exemplary embodiment of nut 100 illustrated, stem 145 is directly attached to head 102. As used in this document, semi-rigid means rigid enough to hold up head 102 when supported from the bottom or other end (from head 102) of stem 145, but flexible enough that it (e.g., stem 145) can be bent without breaking. In addition, as used herein, “at least semi-rigid” means it (e.g., stem 145) may be semi-rigid or stiffer than semi-rigid. Stem 145 being semi-rigid may be desirable for many embodiments because the stiffness allows a climber to place nut 100 higher or further away than she would otherwise be able to reach, and may allow her to place it in cracks that are too narrow for her fingers to fit into. In other embodiments, stem 145 may be substantially flexible, (e.g., like rope or webbing), which may be preferable for large sizes of head 102 where fitting the climber's fingers or hand into the crack is not a problem.

[0046] Stem 145 may have a tensile strength greater than 2000 pounds, or at least 1500 pounds, which will generally allow it to withstand the force generated in a typical lead climber fall. A strength of at least 2000 pounds will allow it to withstand more severe lead climber falls, and greater strengths may be desirable to allow a suitable factor of safety or for applications having a greater load potential. However, lesser strengths may be adequate for some applications. For instance, embodiments for aid climbing where only the climbers static weight is typically supported may have a strength as low as 250 or 300 pounds. Lesser strengths may be all that is attainable for the smallest sizes of devices, but may be preferable to no protection at all where only the smallest cracks are available. Further, a thinner stem 145 may offer the advantage of being able to fit through a narrow constriction, (e.g., in a narrow crack). Thus, there may be a trade-off between strength and slenderness.

[0047] Stem 145 generally has at least one tensile member 144 that substantially provides the tensile strength of the stem. As used in this document, a tensile member substantially provides the tensile strength if at least 75% of the load, when loaded at the rated load of the device, is borne by the tensile member. In many embodiments, stem 145 substantially comprises tensile member 144, and tensile member 144 provides most or all of the tensile strength of stem 145. Tensile member 144 or stem 145 may be made of a non-metal such as a polymer or plastic, which may be a composite material, and may be fiber reinforced. For instance, tensile member 144 may comprise fiber-reinforced plastic (FRP), such as fiberglass or carbon fiber-reinforced plastic (CFRP). Tensile member 144 may comprise a high-strength material such as KEVLAR.

[0048] In the embodiment shown in FIG. 1, tensile member 144 passes through holes 104 (shown in phantom) in head 102, so there are two sections of tensile member 144 forming stem 145. In other embodiments, only one hole 104 may be provided in head 102. Although shown mostly separate with space in between, the sections of tensile member 144 may be in contact with each other, fastened together, or monolithic (e.g., one tensile member 144 in stem 145). Tensile member 144 may be fastened by connector 147, which may keep the two sections of tensile member 144 together, may connect and join two ends of tensile member 144, or both. Connector 147 may be aluminum, plastic, composite, or other suitable material. Tensile member 144 may pass through holes in connector 147. Connector 147 may be crimped on or glued to tensile member 144 or tensile member 144 may be formed within holes in connector 147.

[0049] Loop 170 may be joined with stem 145, and may be configured to attach to a carabiner. As used in this document, “joined with” includes attached to (directly or through another component) or integral with, unless clearly indicated otherwise. In this usage, “joined with” includes, for example, the material of loop 170 passing through a hole in the end of stem 145. In this document, being configured to attach to a carabiner includes that loop 170 is large enough for the carabiner to fit through, and the material from which loop 170 is made is small enough to fit through the gate of a typical carabiner. An example of a carabiner 779 is shown in FIG. 7.

[0050] In other embodiments, loop 170 may be too small for a carabiner to fit through, but may be suitable for a sling (e.g., rope or webbing) which may be sold separately from the device, or may be furnished therewith. As an example, loop 170 may be a hole in the end of stem 145, or may be a link or sling through a hole in stem 145. Thus, loop 170 may be rigid, semi-rigid, or substantially flexible. As used in this document, substantially flexible means capable of withstanding a pulling force, but not a significant pushing force, for instance, like rope or webbing. A loop that is substantially flexible may hold its shape with little force applied (e.g., may support the weight of the loop alone), but generally would not be stiff enough to hold the device erect when held by the loop.

[0051] In some embodiments, loop 170 may be configured to attach to either a carabiner or a sling, (e.g., being large enough for a carabiner to fit through), and also having a large enough radius or diameter of material that a sling can be used without risking that the sling will be cut by loop 170. In addition, although not shown, loop 170 may be covered with a sleeve or coated (e.g., with plastic) to reduce wear or stress from the carabiner or on the sling. In many applications, it may be desirable that loop 170 not be too large, so as to prevent nut 100 from dangling too far from the climber's rack and getting in the way while climbing. As an example, when stretched out, loop 170 may be from two to six inches long. In some embodiments, loop 170 may be a separate piece of material from stem 145, in which case loop 170 may pass through a hole or loop in the end of stem 145 or may connect to stem 145 (e.g., via connector 147). In such embodiments, the separate piece of material may be looped through the hole in the end of stem 145 twice (or more times) to allow it to be doubled (tripled, etc.) when racked, but easily extended if desired for clipping to the climbing rope. Tensile member 144 and/or loop 170 may be, for example, nylon, KEVLAR, SPECTRA, or the like.

[0052] In some embodiments, loop 170 may be formed from the same material as tensile member 144 of stem 145. In such embodiments, loop 170 may be stiff or semi-rigid like stem 145. Alternatively, loop 170 may be flexible (e.g., formed from rope or webbing) and tensile member 144 in stem 145 may be made semi-rigid by treating it or adding additional material. For instance, tensile member 144 may be made of a flexible material which when heat treated or doped becomes significantly stiffer. In such an embodiment, nut 100 may be assembled with a flexible tensile member 144, and then nut 100 from approximately the location of connector 147 up (toward head 102) may then be treated to make stem 145 stiffer. In alternative to heating, such a treatment may involve coating tensile member 144 of stem 145, (e.g., by dipping it into a liquid which then solidifies on the surface), or after penetrating into, tensile member 144 of stem 145. In alternative, or in addition to connector 147, loop 170 or tensile member 144 may be secured with a knot, by twisting, interweaving, or splicing, or with a sewn, crimped, or glued joint. Loop 170 being flexible offers the advantage that the climber may not need to use a quickdraw (two carabiners on a short sling stored on the rack in that configuration) on nut 100 to allow the carabiner clipped to the rope to pivot freely.

[0053] In the embodiment shown in FIG. 1, nut 100 is a chock. Head 102 may be all or substantially a single piece of material such as a metal or a polymer material which (in the case of a polymer) may be fiber reinforced. In this document, being substantially a single piece of material means being at least 75% by weight a continuous piece of the same material, although the material may be made of more than one component, such as a composite of a matrix material and fibers. A single piece of material may also have different properties or compositions in different areas, for example, a composite with more fibers in some areas than others, or a metal that is cold worked in some areas or case hardened on the surface.

[0054] In embodiments where head 102 is metal, it may be aluminum. Head 102 may be solid (e.g., except for holes 104 for tensile member 144 to pass through) (as shown) or may be hollow (e.g., tubular and open on both ends) as would be apparent to one skilled in the art. Head 102 may have curved surfaces (e.g., on the sides) as shown, and the ends of the holes 104 for tensile member 144 may be radiused to reduce the stress on tensile member 144 when nut 100 is weighted. Head 102 may have two or more pairs of substantially opposite surfaces that are situated on substantially opposite sides of head 102. Thus, when nut 100 is placed in a crack or other feature, these substantially opposite surfaces may contact substantially opposite sides of the crack.

[0055] Although tensile member 144 is shown forming top loop 101 above head 102, tensile member 144 may be attached to head 102 in other ways. For instance, the holes 104 in head 102 through which tensile member 144 passes, may be tapered and the process that makes tensile member 144 stiff may also cause tensile member 144 to solidify and secure within holes 104. This may be similar to as shown in FIG. 18 described below.

[0056] There may be a range of sizes of head 102, (e.g., from ⅛inch across to two, three, four, or even more inches across), with different sizes being, for example, {fraction (1/16)} to ½ inch difference in dimension from the next smaller or larger size. Head 102 may be configured to fit into a crack two or more different ways in order to increase its versatility in different size cracks. The different sizes of nut 100 may have different colors, textures or patterns of stem 145, loop 170, head 102, connector 147, or some combination of these, to help the climber quickly identify the desired size from the color, texture or pattern.

[0057]FIG. 2 illustrates another exemplary embodiment of the present invention, which is also a passive device or chock, nut 200. Nut 200 may be similar (in this document similar means similar or identical) to nut 100, except as described otherwise, various notable differences being in stem 245. In general, except as described or shown otherwise, components in this document having reference numbers with the same last two digits may be similar. As examples, except as described otherwise, head 202 may be similar to head 102, stem 245 may be similar to stem 145, tensile member 244 may be similar to tensile member 144, and loop 270 may be similar to loop 170. Stem 245 may be at least semi-rigid, and may comprise tube 248, which may be comprised of plastic or the like, and generally contains tensile member 244 which may be substantially flexible, (e.g., rope or webbing (shown)). Tensile member 244 may attach to solid head 202 [e.g., by passing through (e.g., two) holes in head 202 to form top loop 201], and may form loop 270. In other words, loop 270 may substantially comprise tensile member 244. As used in this document, “substantially comprise” means at least 75% by weight, unless clearly otherwise. The holes in head 202 may be similar to holes 104 shown in head 102 in FIG. 1. Tensile member 244 may be fastened with a knot or sewn joint 272 (shown). Tube 248 may be attachable or attached to head 202, (e.g., via an interference fit, for example, inside a hole in head 202). This fit may be similar to those shown in other figures (e.g., FIGS. 4 and 16) or known in the art. Additional aspects of various components of nut 200 may be as described below with reference to similarly numbered components of camming device 300 in FIG. 3. The embodiment of Nut 200 may be particularly useful in medium sizes, (e.g., one to two inches), where the diameter of stem 245 does not restrict placement, but where it is advantageous to have a semi-rigid stem 245 to facilitate reaching into a crack. Although shown in a wedge shape, head 202 may have another shape such as having a hexagonal, round, or oval cross-section, and may be hollow.

[0058] Referring to FIGS. 3-7, in other embodiments the present invention may be an active camming unit or spring-loaded camming device (SLCD or camming device), for example, camming device 300 shown in FIGS. 3-6. Camming device 300 may be similar to or share features with nut 100 or nut 200 described above, except as stated otherwise. For instance, camming device has head 302, which may have some similarities to head 102 or head 202 described above. Similarly, camming device 300 may have stem 345, which may be similar to stem 245 or stem 145; loop 370 which may be similar to loop 170 or loop 270, and tensile member 344, which may be similar to tensile member 144 or tensile member 244. As shown, loop 370 substantially comprises tensile member 344, and stem 345 also substantially comprises tensile member 344. In addition, although not shown, camming device 300 may have connectors similar to connector 147 described above with reference to FIG. 1. Camming device 300 generally has head 302 which generally has at least three cams 310 (four shown), at least one shaft or axle 314, a plurality of springs 312, and a trigger mechanism 330.

[0059] Cams 310 may be comprised of metal, (e.g., aluminum), or may be comprised partially, substantially, or completely, of a non-metal or non-metallic material such as plastic or a polymer material which may be fiber-reinforced material (e.g., fiber-reinforced plastic or KEVLAR). As used in this document, a cam 310 is said to be substantially comprised of a non-metallic material if less than half of cam 310's weight is metal. For instance, cams 310 may be nylon, fiberglass, or CFRP, or may be plastic with an embedded metal structure or reinforcement. Although aluminum cams may be preferable in certain applications, polymers and other nonmetal materials may be lighter, which may offer an advantage, particularly in larger camming devices 300 where the weigh of cams 310 is a significant portion or most of the weight of the camming device 300 and the weight is substantially more than that of smaller size camming devices. Non-metal cams 310 may need to be wider than metal cams 310, and the increased width may be a disadvantage in smaller sizes of camming device 300. However, in larger size camming devices (e.g., camming device 300), the larger width of non-metal cams 310 may not be a disadvantage. In addition, the larger width will result in a larger moment of inertia which will reduce the tendency for large cams 310 to buckle when loaded. Furthermore, a larger width of cams 310 may reduce the stress and bending moment on axle 314 and allow axle 314 to be made of a softer material, which may be lighter in weight, less expensive, or both.

[0060] As illustrated best in FIG. 5, cams 310 may have stops 513 which may prevent cams 310 from rotating too far. In FIG. 5, the cams 310 are fully open. Stops 513 may prevent cams 310 from rotating too far and allowing the camming device to pull out of the crack where one or more cams 310 rotates to where the tip 617 (as illustrated best in FIG. 6) of cam 310 is against the rock. Rotating too far may also cause a camming device 300 to get stuck in the crack. Stops 513 may be integrally formed from the same continuous piece of material as cams 310. In other embodiments, stops 513 may be embedded or insert molded in cams 510.

[0061] Cams 310 may be made of a material that has a higher coefficient of friction against rock than a metal. In this document, such a material is called a high-friction material. High-friction materials described in this document may, for example, have a coefficient of friction that is twice the coefficient of friction between a metal and the rock, or more. For instance, cams 310 may be made of KEVLAR or a composite material such as fiber-reinforced plastic, the matrix or plastic being selected to increase or increase substantially the coefficient of friction between it and rock. The plastic may be a material commonly used for many other purposes, or may be engineered and selected using techniques known, for example, in the art of engineering rubber for rock climbing shoes, other shoes, or high-performance tires. Cams 310 may have a separate layer or tread 411 (shown best in FIGS. 4 and 6) bonded to or integrally formed with the active outer surface (cam surface) of cams 310. Tread 411 may be a high-friction material. For instance, tread 411 may be plastic or rubber, (e.g., a sticky rubber such as that used on climbing shoes or high-performance racing tires), or may be similar to those materials but harder. Thus, tread 411 may have the property of providing a high coefficient of friction with rock, whereas the material forming the remainder of the cams 310 may have the properties of providing the required strength and stiffness for cams 310. Tread 411 may be attached to cam 310, for instance, by an adhesive. In some embodiments, tread 411 may be a coating applied to cam 310.

[0062] When camming device 300 is placed in a crack or other feature, tread 411 (or the surface of cams 310 where no tread 411 is provided) may form substantially opposite surfaces which may contact substantially opposite sides of the crack or feature. The embodiment of camming device 300, is an example of an embodiment of the present invention wherein substantially opposite surfaces configured to contact the rock are moveable with respect to each other, for example, when cams 310 rotate. In addition, camming device 300 may hold even where the sides of the crack or feature are substantially parallel or even slightly flaring in the direction of the load. Thus, camming device 300 is an example of an embodiment that is configured to anchor to the feature in the rock wherein the two sides of the feature are substantially parallel to each other.

[0063] Although the coefficient of friction obtained from aluminum cams 310 may be adequate for many embodiments, and aluminum may be preferable due to its strength for smaller sizes of camming device 300, higher coefficient of friction between cams 310 and the rock may offer several advantages where usable. First, the higher coefficient of friction may increase the holding power of the camming device 300 and prevent it from pulling out where conditions are marginal. Second, a higher coefficient of friction may allow the cams 310 to have a more aggressive cam profile (greater cam angle), and thus have a greater expansion range. A greater expansion range will allow a given size of camming device 300 to be placed in a greater range of crack sizes. In addition, camming device 300 will function better in an uneven crack where different cams 310 must be expanded drastically different amounts. Third, the more aggressive cam profile will reduce the outward force produced on the rock for a given downward pulling force from a fall. Thus, the chances of the rock breaking are reduced, (e.g., where camming device 300 is placed behind a flake of rock which may be susceptible to breaking if the climber falls). The softer non-metallic cams 310 or treads 411 of many embodiments of the present invention also tend to reduce the likelihood of the rock breaking by deforming slightly and spreading the force over a larger area of rock. The fact that non-metallic cams 310 may be wider than traditional metal cams may also spread the load out on the rock decreasing the peak stress in the rock or point loading.

[0064] Cam angles for aluminum cams 310 may be 14 degrees or less, for example, 13.75 degrees. In contrast, cam angles for polymer cams may be greater than 14 degrees or greater than 15 degrees. In fact, in various embodiments of the present invention, for example wherein cams 310 or treads 411 comprise a high-friction material, may have cam angles of 20 degrees or more. The greater cam angles of the present invention may increase the expansion range, decrease the normal force on the rock, and also increase maximum angle of flair of cracks in which camming device 300 may hold.

[0065] Springs 312 may be steel or stainless steel (e.g., to resist corrosion) and may encircle or wind around axle 314 and be connected to adjacent cams 310. Alternate embodiments of springs 312 may be constructed of lighter materials such as plastic or polymer material which may be fiber reinforced. Still, due to the well-known elastic properties of steel and stainless steel, these materials may be preferable in many embodiments for springs 312 despite their greater density than other materials. Springs 312 are biasing mechanisms, and generally push, pull, rotate, or otherwise bias adjacent cams 312 in opposite directions of rotation around axle 314. In an alternate embodiment, springs 312 may be located within or partially within cams 310. Such an embodiment may, inter alia, reduce the width of head 302 (e.g., the length of axle 314) which may reduce the bending moment on axle 314 and may allow camming device 300 to be used in shallower cracks or narrower pockets.

[0066] Axle 314 may be comprised of metal such as steel, stainless steel, or aluminum, or may be plastic or a polymer material which may be fiber reinforced.

[0067] For instance, axle 314 may be nylon, fiberglass, KEVLAR or CFRP, or may be plastic with an embedded metal structure. Lighter materials may be preferable in particular embodiments to save weight. However, stronger materials such as steel or stainless steel may be preferable, for example, in smaller sizes of camming device 300 where the diameter of axle 314 must be limited. Axle 314 may be hollow, for example, to further save weight. Thus, different sizes of camming device 300 may have different materials and geometries (e.g., solid or hollow) of axle 314. As an example, the smallest camming devices 300 may have solid steel or stainless steel axles 314, while the next larger size or sizes may have hollow steel or solid aluminum axles 314. Larger sizes of camming device 300 may have hollow aluminum axles 314 or solid plastic axles 314. Similarly, the largest sizes of camming devices 300 may have hollow plastic axles. However, in other embodiments, other selections of axle 314 may be preferable for the various sizes of camming device 300. Axle 314 may also comprise a feature or device to keep cams 310 from moving off the ends of axle 314, which may have an interference fit with axle 314. For example, snap rings 418 may secure cams 310 on axle 314. Other devices or methods of attachment, including those known in the art, may be used.

[0068] Head 302 of camming device 300 may also comprise one or more bushings 316 (shown best in FIG. 4) between axle 314 and cams 310. Bushings 316 may be attached to or integral with axle 314 or cams 310, or may be a separate component there between. There may be one or more bushings 316 for each cam 310, or one bushing 316 may serve more than one cam 310 (as shown). Bushings 316 may be open-ended right circular cylinders, and may be comprised of metal (such as steel, stainless steel, bronze, copper, aluminum, aluminum bronze, lead, tin, or brass), a non-metal such as nylon or a low friction material such as Teflon, or a solid lubricant. Some embodiments may have a plurality of concentric bushings 316, which may be comprised of different materials, which may have different or substantially different hardnesses. Bushings 316 may reduce friction, wear, or play (excessive clearance) between axle 314 and cams 310, and may be particularly desirable in embodiments where axle 314, cams 310, or both are comprised of softer materials such as non-metals.

[0069] Loop 370 may be formed with a tensile member 344 which may be flexible and may be completely or substantially non-ferrous or even non-metal. Loop 370 may continue through stem 345 and may continue around axle 314 as shown in FIGS. 4 and 6. Loop 370 may be substantially flexible (e.g., like rope or webbing) and may be configured to attach to a carabiner (e.g., large enough loop and made of small enough cross-section material). Loop 370 may be rope or webbing, and may include a sewn joint 272 (as shown in FIGS. 3 and 4) or a knot 773 (as shown in FIG. 7 and described in reference thereto).

[0070] Stem 345 may utilize a hollow plastic tube 348. In some embodiments, head 302, tensile member 344, and tube 348 may be configured so that tube 348 is attachable to head 302 with an interference fit. Thus, tube 348 may normally be attached to head 302, but it may be possible to pull tube 348 from head 302 and reinstall it (e.g., to replace tube 348 if it is damaged, or to inspect or replace tensile member 344), which removal may be able to be done without requiring the use of tools. In many embodiments, tube 348 may be semi-rigid. Semi-rigid means that tube 348 (or stem 345) is stiff enough to support head 302 when installing or removing camming device 300, but tube 348 (or stem 345) will bend without breaking when loaded in bending . In some embodiments, tube 348 may be flexible enough that it is not damaged when bent, (e.g., by a typical lead fall when camming device 300 is installed in a horizontal crack with stem 345 sticking out). In such a situation, tube 348 may also protect tensile member 344 from damage. In addition, semi-rigid means that tube 348 is stiff enough that it can be used to push on when trigger 330 is pulled to retract cams 310. Tube 348 may be smooth-sided, or may be rough or corrugated. As described above, in some embodiments, it may be possible to replace tube 348 if damaged.

[0071] Tube 348 (alone or along with tensile member 344, loop 370, cams 310, and other components) may be color coded to indicate the size of camming device 300 or head 302. In addition, or in the alternative, tube 348 may have a number, letter, or the size printed on it to indicate its size. Other information may also be printed on tube 348 such as the brand name, instructions for use, warnings, instructions for maintenance or repair, the weight or mass of the device, the date or year of manufacture, the owner's name or other identification, a lot number, a serial number, and/or the like. Tube 348 may have a round cross-section (i.e. be a circular cylinder) or may have another shape cross-section, such as square, hexagonal, octagonal, etc. The shape of cross-section of tube 348, and the surface texture (e.g., smooth, textured, or corrugated) may also indicate the size, or may provide an aesthetic or brand recognition function.

[0072] Camming device 300 shown in FIGS. 3-6 may also comprise stem end 320, which may connect or facilitate the connection of stem 345 to axle or axles 314. Tensile member 344 may pass around axle 314, which eliminates the need to rely on stem end 320 to hold the weight of a climber fall, (e.g., in tension). Stem end 320 may be rigid or nearly rigid (e.g., made of a rigid material) and may help to rotate head 302 to align cams 310 with the direction of the force generated in a fall. In other words, when loaded, stem end 320 may impart a moment on axle 314 to align cams 310 with the direction of the load. Stem end 320 may be constructed of a light-weight metal or non-metal such as aluminum, plastic, fiber-reinforced plastic, or the like, including such materials described in this document for other components. Tube 348 may have a tight or interference fit with stem end 320, (e.g., tube 348 fitting over stem end 320 as shown or vice versa). Thus, stem end 320 may normally remain attached to tube 348, but it may be possible to pull tube 348 from stem end 320, (e.g., to inspect tensile member 344 within tube 348, or to replace tube 348 if it is damaged). In alternate embodiments, tube 348 may be permanently or semi-permanently attached to stem end 320, (e.g., with an adhesive).

[0073] Trigger mechanism 330 may comprise tube 331, which may be concentric with and slide over stem 345 with a clearance fit. Other embodiments may not have a tube 331, but may have the other components of trigger mechanism 330 described in this document. In embodiments having a tube 348, the inside diameter of tube 331 may be slightly greater than the outside diameter of tube 348. Trigger mechanism 330 may also have at least one finger pad 333 (two are shown), and usually two or four attachment points 334 for trigger leads 336. Trigger leads 336 generally connect attachment points 334 of the trigger mechanism 330 to each cam 310 as shown best in FIGS. 3 and 6. There are usually four trigger leads 336 or one for each cam 310 (three cam units may have two trigger leads 336 on the center cam). Tube 311, finger pads 333, and attachment points 334 may be attached or integral, and may be comprised of a non-metal, including those mentioned in this document, for example, plastic. Trigger leads 336 may have a rigid or semi-rigid end that attaches to cams 310, that may be comprised of stainless steel or steel wire (e.g., solid wire) or may avoid ferrous materials or even be non-metallic, and may be comprised of plastic, fiber-reinforced plastic, nylon, or the like. Trigger leads 336 may have a flexible or relatively flexible end that attach to the rigid or semi-rigid ends and to attachment points 334 as shown. A joint may be used to attach the rigid or semi-rigid and flexible or relatively flexible ends of trigger leads 336, which joint may be similar to joint 147 described above with reference to FIG. 1. The flexible or relatively flexible ends of trigger leads 336 may be comprised of wire rope, or may avoid ferrous materials and be rope, webbing, plastic, fiber-reinforced plastic, or the like. Non-metals, and particularly high-strength non-metals, may have the advantage that they are lighter weight. The flexible or relatively flexible ends of trigger leads 336 may be continuous for two adjacent cams 310 and may pass through one or more holes in attachment points 334, thus easing adjustment of the relative lengths of adjacent trigger leads 336. In some embodiments, trigger leads may be the same material throughout, which may or may not vary in diameter, cross-sectional area, shape, coating, or other treatment, and may be non-metallic.

[0074] Camming device 300 may be operated like a syringe by placing a finger on each finger pad 333 of trigger 330, and the thumb on the end 249 (opposite head 302) of stem 345 (e.g., tube 348). The climber may then pull with her fingers while pushing with her thumb to retract cams 310. Thus, tube 348 may be loaded in compression (e.g., axially) during installation of device 300, and may carry all or substantially all of the compressive load. Once cams 310 are retracted, the camming device 300 may be inserted into a suitably-sized crack (e.g., in rock) where the trigger 330 is released and the springs 312 rotate the cams 310 allowing them to expand until the treads 411 or active surface of cams 310 contact the surface of the rock. Then the climber may let go of the camming device 300, and clip the climbing rope into loop 370 with a carabiner, where appropriate using a separate sling, runner, or quick-draw. Later, when the second climber reaches camming device 300, he may remove it by retracting cams 310, again by pulling on trigger mechanism 330 while pressing on stem 345.

[0075] Although only one axle 314 is shown in FIG. 3, a camming device in accordance with the present invention may have two axles. An exemplary embodiment of a double-axle spring-loaded camming device 700 is shown in FIG. 7. Camming device 700 has head 702, stem 745, trigger mechanism 730, and loop 770, which may be similar to their counterparts described above with the same last two digits of the reference numbers. Head 702 has two axles 714, which, in the exemplary embodiment illustrated, are hollow. Axles 714 may be similar to 314 described above, and vice versa.

[0076] Camming device 700 may function similarly to camming device 300, except as described herein and as apparent to a person of skill in the art. Specifically, camming device 700 with two axles 714 may have a larger expansion range (e.g., than camming device 300), allowing, inter alia, a particular camming device 700 to be placed in a larger range of crack sizes. However, camming devices 700 with two axles 714 must have large holes 715 in the cams 310, thus limiting their strength for a given material. Thus, there is a tradeoff between having one or two axles 314 or 714, and each design may have applications in which it is preferred.

[0077] Stem 745 may have tube 748 as shown, which may be similar to tubes 348 or 248 described above. Head 702 may comprise stem end 920 (shown separately in FIG. 9) which may be comprised of a rigid material such as a metal (cut from plate or bar stock or forged) or a non-metal described in this document. For instance, stem end 920 may be comprised of aluminum or a polymer, which may be fiber reinforced such as fiber-reinforced plastic. Embodiments of stem end 920 may have holes 924 for axles 714 to pass through, which may be a close or slight interference fit, and hole 922 for tensile member 744 to pass through, which may have rounded or radiused ends to avoid cutting tensile member 744. Tube 748 may be compressed slightly at the end (top end as shown) to fit over the end of stem end 920 as shown in FIG. 9. Tube 748 may fit over stem end 920 up to axle 714 or to ledge 926 as shown in FIG. 9. As illustrated in FIG. 7, ledge 926 may be further from axle 914 than cams 710 travel, thus preventing tube 748 from interfering with cams 710.

[0078] In the exemplary embodiment shown, camming device 700 has tensile member 744 which is rope, joined by knot 773. Knot 773 may be, for example, a double fisherman's knot (shown) or a triple fisherman's knot. Loop 770 may be configured to attach to carabiner 779 as shown. In various embodiments, tensile member 744 may be similar to tensile members 144, 244, or 344, for example, tensile member 744 may be webbing.

[0079] Alternate embodiments of stem ends (e.g., alternates to stem end 320 of camming device 300) and stems (e.g., 345), are illustrated in FIGS. 8 and 10-13. Such stems and stem ends may also have applications to a double-axle camming devices (e.g., 700). FIG. 8 illustrates stem end 820 which may be similar to stem end 920 except that stem end 820 is configured for a single-axle camming device (e.g., 300). FIG. 8 illustrates tube 348 extending to axle 314 (not shown), or to holes 824 for axle 314. However, a ledge, similar to ledge 926 could also be used. FIG. 8 also illustrates a tensile member (here 844) that is rope, used with a single-axle camming device (e.g., 300).

[0080] End 249 of tube 248, 348, and 748 may be a plain end (as shown in FIGS. 2, 3, 4, and 7) which may have rounded edges to avoid any risk of damage, (e.g., to tensile member 344, for example, when camming device 300 is operated (as described above)). As illustrated in FIGS. 10 and 11, in some embodiments, tube 1048 may be used. Tube 1048 may be similar to tube 348 except as described in this document. Specifically, tensile member 344 may exit tube 1048 through one or more holes 1053 in the wall of tube 1048 as shown in FIGS. 10 and 11. Holes 1053 may be square or rectangular as shown, or may be round or oval. Also as shown in FIGS. 10 and 11, there may be a separate end cap 1051 on the end of tube 1048. End cap 1051 may be attached to tube 1048, for example, with an interference fit or an adhesive, or may be integral with tube 1048. As further illustrated in FIGS. 10 and 11, a stem (e.g., stem 1048) may terminate at the axle (e.g., 314) without a separate stem end (e.g., 320 or 820). The axle 314 may pass through a slot, indentation, or notch in the end (top end as shown) of tube 1048, or tube 1048 may simply press against axle 314. Tensile member 344, which may also form loop 370, may pass over or go around axle 314. The embodiment of stem 345 illustrated in FIG. 10 may not offer the benefit of aligning cams 310 as illustrated (e.g., in FIG. 3), but may be lighter and less expensive than other embodiments. Also as shown in FIG. 10, sewn joint 272 may be located within a tube (e.g., 1048) of stem 345. The size of the webbing and the inside diameter of the tubing may be selected so that sewn joint 272 fits tightly inside the tube 1048, thus helping to hold the tube 1048 in place, (e.g., against axle 314). In addition, locating sewn joint 272 inside tubing 348 may also protect sewn joint 348 from wear or damage. In other embodiments, sewn joint 272 may be located within loop 370, (e.g., a slight distance from the end of loop 370), which may help to hold loop 370 open for easy attachment of a carabiner.

[0081]FIG. 12 illustrates an embodiment 1245, of a stem, wherein essentially the stem end is integral with the stem. In other words, no separate stem end (e.g., 320) is provided. Stem 1245 may be similar to stem 345, except as stated otherwise in this document. Stem 1245 has hole 1224 for axle 314 (not shown) which may be similar to hole 824 described above with reference to FIG. 8 except that hole 1224 is through tubular material, i.e. tube 1248. Tube 1248 may be similar to tube 348, except as described in this document. Tensile member 344 (not shown in FIG. 12, but similar to what is shown in other drawing figures) may go around axle 314.

[0082]FIG. 12 also illustrates that the tube (e.g., 1248), may be tapered at the end, (e.g., end 1249) where the bending moment is less. Tube 1248 may be tapered along part of its length as shown, (e.g., beyond where trigger 330 may slide on stem 1245) or along the entire length. In addition, the wall thickness may vary along the length of tube 1248, and may be thinner at end 1249. In contrast, in other embodiments, the tube may be a substantially constant diameter with a substantially constant wall thickness in order to minimize fabrication costs. Stem 1245 may provide some rigidity (e.g., of stem end 320 described above) to align the cams, which may be adequate if tube 1248 is stiff enough. With stem 1245, replacement of the stem may be more difficult (compared to other embodiments of the present invention) or impossible, but stem 1245 may be light weight and inexpensive.

[0083]FIGS. 13 and 14 illustrate an additional alternate embodiment stem, stem 1345. In this exemplary embodiment, stem 1345 is comprised of a plurality of layers of tensile member 344 (e.g., webbing) which may be sewn together (e.g., along the entire length of stem 345). Tensile member 344 may pass around axle 314. In such embodiments, bushing 1316 may be in between tensile member 344 and axle 314. The sewing may provide adequate stiffness for stem 1345, or the stiffness may be increased by sewing in additional strip 1341. Strip 1341 may be a strip of plastic or similar material, which may be flat, for instance with a rectangular cross-section, and may be as wide as tensile member 344. Strip 1341 may be relatively stiff, for example, semi-rigid, and may be attached to or integral with bushing 1316. In some embodiments, stem 1345 may have an external sleeve 1348, (e.g., for protection or added stiffness). Sleeve 1348 may, for example, have a square or rectangular cross-section. In other embodiments, sleeve 1348 may have a round cross-section. Sleeve 1348 may be removable and replaceable. Tensile member 344 may also form loop 370 as shown in other figures. The tensile member 344 may be made of a substantially flexible material such as rope or webbing (shown). Tensile member 344 may be nylon or a high-strength material such as KEVLAR or SPECTRA.

[0084] In various other embodiments, stem 345 may not have a separate tube 348 and may be comprised of a semi-rigid tensile member 344, similar to tensile member 144 described above, and may be fiber-reinforced plastic. In these embodiments, the stem 345 may also forgo any load bearing ferrous materials such as wire rope or cable. Thus, in many embodiments with or without a tube, (e.g., 348), stem 345 may utilize no load bearing ferrous materials (e.g., cable or wire rope) at all.

[0085] In various embodiments of the present invention, as illustrated in FIG. 15, the stem may have two parts, or there may be two stems. Camming device 1500 includes an “H” or square “U” shaped stem 1545, one example of which is shown.

[0086] Stem 1545 attaches to the ends of head 1502, for instance, at axle 1514 as shown. Stem 1545 may be similar to stem 345 described above except as described in this document, including that tube 1545 may have horizontal thumb beam 1547. Stem 1545 may comprise tubes 1548, which may be similar to tube 348 described above. Camming device 1500 may have three (as shown) or more (e.g., four) cams 310, springs 312, attachment points 334, and trigger leads 336, which may be as described above with reference to FIG. 3. Stem 1545 may contain tensile member 344 as shown, which may be as described above with reference to FIG. 3.

[0087] Camming device 1500 may function similarly to camming devices 300 and 700, except as described herein and apparent to a person of skill in the art. For instance, camming device 1500 may have trigger mechanism 1530, which may have one, two, or three finger pads 1533, which may include internal or external finger pads or both (as shown), which may be used in opposition to a thumb on beam 1147 to retract cams 310.

[0088] Tensile member 344 of camming device 1500 may be attached to axle 1514 in ways similar to those described above (e.g., via stem end 320). Additional exemplary embodiments and methods of attachment are illustrated in FIGS. 16 through 17, which, although illustrated for camming device 1500, may also be applicable in many or all respects to single-stem camming units such as camming device 300. In addition to the embodiments shown, in embodiments wherein axle 1514 is hollow, tensile member 344 may pass through axle 1514, generally with rounded ends of axle 1514 to avoid cutting tensile member 344.

[0089]FIG. 16 illustrates an exemplary embodiment wherein tensile member 344 passes through a hole 1615 in axle 1514 and forms a knot 1512. There may also be a recess in axle 1514 for tube 548 as shown, which may have an interference fit as described above for other embodiments. In alternative, or in addition, a recess may be provided in axle 1514 for knot 1512. In this and other embodiments, washers 1617 may be provided (e.g., between cam 310 and tube 1545 or knot 1512). In embodiments wherein axle 1514 is hollow, hole 1615 may extend through one side of axle 1514, while a large hole, similar to the recess shown, may extend through the other side of axle 1514. Hole 1515 may be just large enough for tensile member 344 to pass through, while recess or hole 1345 may be sized to receive the end of tube 1548.

[0090] In an alternate exemplary embodiment shown in FIG. 17, stem ends 1720 may attach to axle 1514 as shown, and tensile member 244 and tube 1548 may attach to stem ends 1720. Stem ends 1720 may be similar to stem end 820 described above, with holes for axle 1514 and tensile member 244. Stem end 1720 may provide a moment on axle 1514 to align cams 310 as described above for other embodiments. Ledge 1726 may keep tube 1548 from interfering with cams 310 and allow the width of the head 1502 of camming device 1500 to be minimized. In the embodiment shown in FIG. 17, tensile member 244 may be webbing, and the two layers of tensile member 244 may be sewn together, (e.g., from one stem end 1720 to the other or throughout loop 270 (loop 270 shown in FIG. 2)). Three layers of tensile member 244 may be sewn together at the end of loop 270 to increase the thickness where the carabiner usually contacts loop 270.

[0091]FIG. 18 illustrates a further alternate embodiment of camming device 1500, wherein, similar to nut 100, the tensile member 144 has its own stiffness, and separate tubes (or tube) (e.g., 1545) external to the tensile member may be omitted. For instance, the stem or stems (e.g., 1545) may be made substantially of fiber-reinforced plastic, and may forgo any load bearing ferrous materials such as cable or wire rope. In such an embodiment, beam 1547 may attach, or be integral with, tensile member 144. Tensile member 144 (in this embodiment, a solid material that is at least fairly incompressible) may be formed within, or inserted within, a tapered hole through axle 1514. Alternate embodiments may involve tensile member 144 surrounding axle 1514, (e.g., similar to stem end 1720). In one embodiment, tensile member 144 may attach to axle 1514 and be configured similarly to what is shown in FIG. 13. In one embodiment, a circumferential groove in axle 1514 may secure tensile member 144 to the end of axle 1514. In embodiments wherein tensile member 144 has its own stiffness, camming device 1500 may have a loop which may be similar to what is described above for loop 170.

[0092] FIGS. 19-21 illustrate a further exemplary embodiment 1900 of the present invention installed in a crack or feature that has substantially opposite and substantially parallel sides. As shown, embodiment 1900 is a single-cam camming device, and comprises cam or head 1901, stem 1948, and loop 1970. Head 1901 may be, for example, aluminum, or a non-metal, including those described in this document, for instance, for cams 310. Head 1901 may have a solid or hollow body and may attach to stem 1948, (e.g., via pin 1914). Pin 1914 may be solid or hollow and may be made of the materials described in this document for an axle (e.g., 314). Loop 1970 may be attached to or integral with stem 1948, at the opposite end of stem 1948 from head 1901.

[0093] Head 1901, may, on at least one side, have a high-friction material 1911, which may be a coating or may be bonded or attached to head 1901, for example, with an adhesive. High-friction material 1911 may be a polymer, and may be similar to tread 411 described above. In some embodiments, (e.g., where head 1901 is substantially comprised of a non-metal, high-friction material) 1911 may be integral with head 1901. In other embodiments, head 1901 may have a high-friction material 1911 on only one side (e.g., as shown). Thus, embodiment 1900 may have two substantially opposite surfaces one of which may have a high-friction material 1911, and the other surface may or may not have a high-friction material 1911. In either case, embodiment 1900 is generally configured to anchor to a feature in the rock with one surface in contact with one side of the feature, and the other surface in contact with the other substantially opposite side of the feature. In embodiments having only one surface of a high-friction material 1911, stem 1948 (e.g., tensile member 244) may attach to head 1901 near or proximate the side that does not have high-friction material 1911.

[0094] Head 1901 may be a cam, and may be shaped, for example, as shown, so that as head 1901 is rotated the dimension across it continuously changes. Thus, embodiment 1900 may function in a range of crack or feature sizes. In other embodiments, head 1901 may have multiple surfaces, which may be arranged in substantially opposite pairs (e.g., parallel, or substantially parallel planes), that may have different distances apart for different size cracks or features. For instance, Head 1901 may have six sides (e.g., the cross-sectional shape of an irregular hexagon). In such an embodiment, the surfaces further away from where the stem or tensile member attaches may have a high-friction material, while the surfaces closer to where the stem or tensile member attaches may not have a high-friction material (e.g., may be metal, such as aluminum). In other embodiments, Head 1901 may be long and narrow (e.g., a tube chock) and may include structure that allows the length to be changed and fixed in various positions for various width features (e.g., cracks). This structure may include threads, and the device may be configured to expand via a spring and then be secured in the expanded position by rotating a threaded portion or nut. Again, in such embodiments the surface configured to contact the rock that is further away from where the stem or tensile member attaches may have a high-friction material, while the surface configured to contact the rock that is closer to where the stem or tensile member attaches may not (e.g., may be metal, such as aluminum). Many other similar shapes would be apparent to a person skilled in the art who studies this document.

[0095] Embodiment 1900 may be considered a passive camming device, at least embodiments thereof without a biasing mechanism (described below). It may also be possible to place embodiment 1900 as a passive nut where there is a constriction in the crack or feature.

[0096] Embodiment 1900 may include a biasing mechanism to rotate head 1901 within the crack in the rock. Such a biasing mechanism may help to keep embodiment 1900 firmly placed in the crack while the climber climbs. For instance, head 1901 may include lever 1921, which may be biased by spring 1912 against the side of the crack. In addition, or in the alternative, stem 1948 may include strip 1941, which may be semi-rigid or elastic, and may be similar to strip 1341 described above, except as described herein. Strip 1941 may be a non-metal, (e.g., plastic, such as nylon). But in some embodiments, strip 1941 may be metal, for example, spring steel. Strip 1941 may also press against the side of the crack to rotate head 1901 against the sides of the crack and keep embodiment 1900 of the present invention in place. As used in this document, lever 1921 and strip 1941 are examples of biasing mechanisms. Other biasing mechanisms that tend to rotate head 1901 within the natural feature in the rock, or tend to push against one side of the feature, may be apparent to a person skilled in the art.

[0097] Some embodiments of the present invention, including embodiment 1900 shown in FIG. 19, include both a high-friction material 1911 and a biasing mechanism (e.g., lever 1921 or strip 1941). However, other embodiments, have a high-friction material 1911 and no biasing mechanism. Still other embodiments have a biasing mechanism with no high-friction material 1911. For instance, head 1901 may be shaped with a curved surface on one side and a point or pointed surface on a substantially opposite side, (e.g., a TRICAM or similarly shaped device). However, such a device in accordance with the present invention may include a biasing mechanism (e.g., lever 1921 or strip 1941), which may help to hold the device in the feature (e.g., crack) so that rope drag and other forces are less likely to cause the device to come out of the crack or feature prematurely. The present invention also includes a generally hexagonal device with a biasing mechanism so that rope drag and other forces are less likely to cause the device to displace from the crack or feature.

[0098] In embodiments 1900 having biasing mechanisms, the climbers may need to retract the biasing mechanism (e.g., from the side of the crack) to install or remove the device. Although not shown, structures or components may be provided to facilitate retracting the biasing mechanism. Various embodiments of such components would be apparent to a person of ordinary skill in the art who has studied this document.

[0099] Stem 1948, loop 1970, or both, may be comprised of a tensile member, (e.g., 244, which may be, for example, webbing), and may have a knot or sewn joint 272. Other embodiments exist besides the one illustrated in FIG. 19. For example, stem 1948 may be similar to other stems described in this document. For instance, stem 1948 may be semi-rigid and may include a tube that tensile member 244 may pass through. In some embodiments stem 1948 may consist only of tensile member 244. In some embodiments, stem 1948 may be flexible, for example, like rope or webbing. In some embodiments, stem 1948 may comprise or consist of a semi-rigid material such as described above for tensile member 144. In such an embodiment, the stiffness of tensile member 144 may allow it to press against the surface of the crack and form an integral biasing mechanism.

[0100] Some embodiments of the present invention may have a high-friction material 1911 on substantially opposite surfaces of head 1901. In such embodiments, the high-friction material may help to keep the device from falling out of the feature (e.g., crack), for instance, in embodiments without biasing mechanisms. The high-friction material may also reduce the stress in the rock (e.g., normal to the surface of the natural rock feature) and thus reduce the likelihood that the rock will break, for example, in a severe fall or where the strength of the rock is marginal.

[0101] In another embodiment of the present invention, the device may be a slider. A slider in accordance with the present invention may have two surfaces that contact the rock, and the two surfaces may be movable with respect to each other. Embodiments may be configured to anchor to features in the rock that have substantially parallel sides. In such an embodiment, the head or part of the head may have a high-friction material and surface on one side, and a smooth, lower-friction surface on the other side. This lower-friction surface, may be, for example, bare metal (e.g., steel), which may be machined, or even polished, for smoothness. In other embodiments, the lower-friction surface may include a low-friction material, for example, Teflon. The lower-friction surface may have a groove, channel, indentation, or slot, in which a semi-sphere, block, ridge, or other similar shaped sliding component or feature of a sliding component may slideably adjoin the head or other part of the head. The sliding component may also have a low-friction surface in contact with the low-friction surface of the head. These two low-friction surfaces may be hard or hardened, and may have different hardnesses to prevent galling. A solid lubricant may be used between sliding surfaces in this and other embodiments. The sliding component may also have a surface with a high-friction material, generally substantially opposite the low-friction surface such that the high-friction material is configured to contact the rock (e.g., the side of the crack). A stem or tensile member may be attached to the head, which may be joined with a loop as described for other embodiments. The tensile member may be attached to the head proximate the high-friction material, proximate the lower-friction surface, or both. The tensile member may be one of the embodiments of a tensile member described above, or may be wire rope (e.g., steel or stainless steel). A biasing mechanism, for example, a spring, may push the sliding component away from the stem or loop, and the head may be shaped like a wedge so that the biasing causes the sliding component and head to push against substantially opposite sides of the crack or other feature.

[0102] A trigger mechanism may further be provided to retract the sliding component. The slider may adopt various other features of embodiments of the present invention described in this document. In addition, the use of high-friction materials may offer many of the benefits described for other embodiments.

[0103] Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of any or all the claims. As used in this document, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, no element described in this document is required for the practice of the invention unless expressly described as “essential” or “critical”.

[0104] In addition, modifications may be made to the disclosed embodiments without departing from the scope of the invention. The scope of the invention is therefore not limited to the disclosed embodiments but is defined by the appended claims. In other words, other variations and modifications of the present invention will be apparent to those of ordinary skill in the art, and it is the intent of the appended claims that such variations and modifications be covered. The particular values and configurations discussed above can be varied, are cited to illustrate particular embodiments of the present invention, and are not intended to limit the scope of the invention. It is contemplated that the use of the present invention can involve components having different characteristics as long as the elements of at least one of the claims below, or the equivalents thereof, are included. 

What is claimed is:
 1. A device for anchoring to natural features in rock, said device comprising: a head; a stem: attached to said head, being at least semi-rigid, having a tensile strength greater than 1500 pounds, and comprising at least one polymer tensile member, said tensile member substantially providing said tensile strength; and a loop: joined with said stem, and configured to attach to a carabiner.
 2. The device according to claim 1, said head being substantially a single piece of material.
 3. The device according to claim 1, said head substantially comprising polymer material.
 4. The device according to claim 3, said polymer material being fiber reinforced.
 5. The device according to claim 1, said device being a spring-loaded camming device, said device comprising: at least three cams; at least one axle; a plurality of springs; and a trigger mechanism.
 6. The device according to claim 1: said loop substantially comprising said tensile member; said stem comprising said tensile member; and said tensile member passing around said axle.
 7. The device according to claim 1, said stem comprising a hollow plastic tube, said tensile member passing through said tube, said tensile member being substantially flexible.
 8. The device according to claim 7, said tube and said head being configured so that said tube is attachable to said head with an interference fit, said tube being color coded to indicate the size of said head.
 9. The device according to claim 1, said stem substantially comprising fiber-reinforced plastic.
 10. A camming device configured to attach to natural features in rock, said device comprising: a head having at least one cam, said cam comprising at least ten percent by weight a non-metallic material; and a stem attached to said head, said stem comprising at least one non-metallic tensile member.
 11. The camming device of claim 10, said head further comprising a biasing mechanism.
 12. The camming device of claim 10, said non-metallic material being a high-friction material.
 13. The camming device of claim 10, said head further comprising: at least one axle; at least three cams on said at least one axle, each said cam substantially comprised of a non-metallic material; and a trigger mechanism.
 14. The camming device of claim 13, said axle being hollow.
 15. The camming device of claim 13, said axle being substantially comprised of aluminum.
 16. The camming device of claim 13, said axle being substantially comprised of a polymer material.
 17. The camming device according to claim 13, said stem comprising a hollow plastic tube containing said tensile member, said tensile member being substantially flexible, and said tensile member forming a loop configured to attach to a carabiner.
 18. The camming device according to claim 13, said trigger mechanism comprising a plurality of substantially non-metallic trigger leads attached to said cams.
 19. A device for attaching to a feature in rock, the feature having at least a first side and a second side, the first side being substantially opposite the second side, said device comprising at least: a head having at least a first surface and a second surface, said first surface and said second surface being on substantially opposite sides of said head; a tensile member attached to said head; said device being configured to anchor to the feature with at least said first surface in contact with the first side and at least said second surface in contact with the second side; and said first surface comprising a high-friction material.
 20. The device of claim 17, said second surface being metal.
 21. The device of claim 18, said tensile member being proximate said second surface.
 22. The device of claim 17, said second surface comprising a high-friction material.
 23. The device of claim 17, said device further comprising a biasing mechanism.
 24. The device of claim 17, said first surface being movable with respect to said second surface.
 25. The device of claim 17, said device being configured to anchor to the feature wherein the first side is substantially parallel to the second side. 